The present invention relates to a structure of wiring connection, and more particularly to a structure of wiring connection applied to plate-like electric wirings called as bus bars.
In internal wirings inside an industrial electric device, in which large currents flow, narrow plate-like wirings (plate-like wirings) called as bus bars are often employed as shown in FIG. 42.
Generally, in a device like a large-capacity inverter (DC/AC converter) that switches large currents quickly therein, the two bus bars that flow currents of equal magnitude and of opposite directions to each other are structured in layers and in parallel to be closer as possible, like a bus bar 101 and a bus bar 102 in FIG. 42, which is one of ordinary-seen example of such bus bar formations. With such a structure, magnetic fields created by currents of opposite directions reduce each other, so that the inductance in the entire structure becomes lower than that of other bus bar formations.
By the way, in case that the pair of bus bars inside an electric device has to connect with external wirings to send or receive current, each bus bar has to have a xe2x80x9cconnecting portionxe2x80x9d for it. Suppose the bus bar 101 and the bus bar 102 in FIG. 42 were internal wirings, a bus bar 111 and a bus bar 112 are to be the external ones. The bus bar 101 is to connect with the bus bar 111, and the bus bar 102 is to connect with the bus bar 112. The external wirings should have the same or similar structures and formation as those of the internal wirings, if reduction of inductance in an entire electric circuit is intended. And connection of these bus bars should be carried out by, for instance, fastening with bolts and nuts considering ease of assembly and maintenance. Consequently, a hole for the fastening is made in each of the connecting portions of the bus bars 101, 102, 111 and 112. And not to interfere the two bolts each other and not to interfere one bolt and a fastening tool when another bolt is fastening, the structure of the connecting portions has to be such that as shown in FIG. 42. Therefore, the partial inductance of this connecting portion becomes far larger than that at the other portion of bus bar pair formation, because the bus bar at the connecting portion cannot be so constructed to be near each other.
The present invention has been achieved through such consideration and an object of the invention is to provide a structure of wiring connection capable of suppressing an increase of inductance effectively.
To achieve the above object, according to one aspect of the present invention, a structure of wiring connection has: a first wiring that extends as a narrow plate having two main faces and having a predetermined plate width, and provided with a main portion, at least one connecting portion and an elbow portion defined as a portion between the main portion and the connecting portion thereof; a second wiring that extends as a narrow plate having two main faces and having a predetermined plate width, and provided with a main portion, at least one connecting portion and an elbow portion defined as a portion between the main portion and the connecting portion thereof; a third wiring that extends as a narrow plate having two main faces and having a predetermined plate width, and provided with a main portion, at least one connecting portion and an elbow portion defined as a portion between the main portion and the connecting portion thereof, the connecting portion of the first wiring and the connecting portion of the third wiring being in contact with each other through a predetermined area; and a fourth wiring that extends as a narrow plate having two main faces and having a predetermined width, and provided with a main portion, at least one connecting portion and an elbow portion defined as a portion between the main portion and the connecting portion thereof, the connecting portion of the second wiring and the connecting portion of the fourth wiring being in contact with each other through a predetermined area. Between any one of the first wiring to the fourth wiring and one of the other wirings, a specific distance defined as a distance between gravity centers in sections of two corresponding wirings of the first wiring to the fourth wiring cut along a plane vertical to each main face of the two corresponding wirings is less than the predetermined plate width of each of the two corresponding wirings. The main portion of the first wiring and the main portion of the second wiring run together in parallel facing each one of main faces thereof, and the main portion of the third wiring and the main portion of the fourth wiring run together in parallel facing each one of main faces thereof.
In such a structure, it is preferable that each predetermined plate width of the first wiring to the fourth wiring is the same width.
In such a structure, it is preferable that the elbow portion of the first wiring and that of the third wiring are in contact with each other, and the elbow portion of the second wiring and that of the fourth wiring are in contact with each other.
In such a structure, it is preferable that the elbow portion of the first wiring and that of the third wiring are in contact with each other to be sandwiched between the elbow portion of the second wiring and that of the fourth wiring.
In such a structure, it is preferable that a part of the elbow portion of the first wiring and that of the third wiring are in contact with each other, and another part of the elbow portion of the first wiring is sandwiched between the elbow portion of the second wiring and that of the fourth wiring.
In such a structure, it is preferable that each connecting portion of the first wiring to the fourth wiring is detachable from a corresponding connecting portion thereof.
According to another aspect of the present invention, a structure of wiring connection has: a first wiring that extends as a narrow plate having two main faces and having a predetermined plate width, and provided with a main portion, at least one connecting portion and an elbow portion defined as a portion between the main portion and the connecting portion thereof; a second wiring that extends as a narrow plate having two main faces and having a predetermined plate width, and provided with a main portion, at least one connecting portion and an elbow portion defined as a portion between the main portion and the connecting portion thereof; a third wiring that extends as a narrow plate having two main faces and having a predetermined plate width, and provided with a main portion, at least one connecting portion and an elbow portion defined as a portion between the main portion and the connecting portion thereof; a fourth wiring that extends as a narrow plate having two main faces and having a predetermined plate width, and provided with a main portion, at least one connecting portion and an elbow portion defined as a portion between the main portion and the connecting portion thereof, the connecting portion of the first wiring and the connecting portion of the fourth wiring being in contact with each other through a predetermined area; a fifth wiring that extends as a narrow plate having two main faces and having a predetermined width, and provided with a main portion, at least one connecting portion and an elbow portion defined as a portion between the main portion and the connecting portion thereof, the connecting portion of the second wiring and the connecting portion of the fifth wiring being in contact with each other through a predetermined area; and a sixth wiring that extends as a narrow plate having two main faces and having a predetermined width, and provided with a main portion, at least one connecting portion and an elbow portion defined as a portion between the main portion and the connecting portion thereof, the connecting portion of the third wiring and the connecting portion of the sixth wiring being in contact with each other through a predetermined area. Between any one of the first wiring to the sixth wiring and one of the other wirings, a specific distance defined as a distance between gravity centers in sections of two corresponding wirings of the first wiring to the sixth wiring cut along a plane vertical to each main face of the two corresponding wirings is less than the predetermined plate width of each of the two corresponding wirings. The main portion of the first wiring, the main portion of the second wiring and the main portion of the third wiring run together in parallel facing each one of main faces thereof, and the main portion of the fourth wiring, the main portion of the fifth wring and the main portion of the sixth wiring run together in parallel facing each one of main faces thereof.
In such a structure, it is preferable that each predetermined plate width of the first wiring to the sixth wiring is the same width.
In such a structure, it is preferable that the first wiring is provided with a region where part thereof is curved such that when the first wiring to the sixth wiring are in a circuit system, and the fourth wiring and the fifth wiring are connected with each other at somewhere therein, inductance for a current through the first wiring, the fourth wiring, the fifth wiring and to the second wiring is equal to inductance for a current through the third wiring, the sixth wiring, the fifth wiring and to the second wiring.
In such a structure, it is preferable that part of the first wiring is provided with a region where the plate width thereof is changed such that when the first wiring to the sixth wiring are in a circuit system, and the fourth wiring and the fifth wiring are connected with each other at somewhere therein, inductance for a current through the first wiring, the fourth wiring, the fifth wiring and to the second wiring is equal to inductance for a current through the third wiring, the sixth wiring, the fifth wiring and to the second wiring.
In such a structure, it is preferable that part of the first wiring is provided with a region where plate thickness thereof is increased such that when the first wiring to the sixth wiring are in a circuit system, and the fourth wiring and the fifth wiring are connected with each other at somewhere therein, inductance for a current through the first wiring, the fourth wiring, the fifth wiring and to the second wiring is equal to inductance for a current through the third wiring, the sixth wiring, the fifth wiring and to the second wiring.
In such a structure, it is preferable that each connecting portion of the first wiring to the sixth wiring is detachable from a corresponding connecting portion thereof.
In the structure of the above one aspect, it is preferable that the first wiring and the second wiring are used as internal wirings in an electric device module, and the connecting portion and the elbow portion of the first wiring and those of the second wiring are exposed on a surface of the electric device module.
In such a structure, it is preferable that the connecting portion of the first wiring and that of the second wiring are provided on a surface of a box-like shell of the electric device module, while the electric device module is a power transistor module, a power diode module or an intelligent power module.
In such a structure, it is preferable that the elbow portions continuing each connecting portion of the first wiring and that of the second wiring are provided on the same surface of the box-like shell of the electric device module as that the connecting portions are provided.
In such a structure, it is preferable that the elbow portions continuing each connecting portion of the first wiring and that of the second wiring are provided on the adjoining surface of the box-like shell of the electric device module to that the connecting portions are provided.
In the structure of the above another aspect, it is preferable that the first wiring to the third wiring are used as internal wirings of the electric device module, and the connecting portion and the elbow portion of the first wiring, those of the second wiring and those of the third wiring are respectively exposed on a surface of the electric device module.
In such a structure, it is preferable that each connecting portion of the first wiring to the third wiring is provided on a surface of the box-like shell of the electric device module, while the electric device module is a power transistor module, a power diode module or an intelligent power module.
Besides, according to still another aspect of the present invention, a wiring connection method prepares first to fourth wirings that respectively extends as narrow plates each having two main faces and having a predetermined plate width, and provided with a main portion, at least one connecting portion and an elbow portion defined as a portion between the main portion and the connecting portion thereof; connects the connecting portion of the first wiring and the connecting portion of the third wiring so as to be in contact with each other through a predetermined area; and connects the connecting portion of the second wiring and the connecting portion of the fourth wiring so as to be in contact with each other through a predetermined area. Between any one of the first wiring to the fourth wiring and one of the other wirings, a specific distance defined as a distance between gravity centers in sections of two corresponding wirings of the first wiring to the fourth wiring cut along a plane vertical to each main face of the two corresponding wirings is less than the predetermined plate width of each of the two corresponding wirings. The main portion of the first wiring and the main portion of the second wiring run together in parallel facing each one of main faces thereof, and the main portion of the third wiring and the main portion of the fourth wiring run together in parallel facing each one of main faces thereof.